Field of the Invention
Lately, an image forming apparatus such as a scanner, a copier, a printer, and a facsimile is required to be able to form an image on various types of sheets and to be able to discharge the sheet orderly on a sheet discharge tray. However, in a case when a sheet with relatively small (weak) stiffness is discharged to the sheet discharge tray, a front end of the sheet might hang down under its own weight and the sheet is not stacked orderly on the sheet discharge tray.
Description of the Related Art
Lately, an image forming apparatus such as a scanner, a copier, a printer, and a facsimile is required to be able to form an image on various types of sheets and to be able to discharge the sheet orderly on a sheet discharge tray. However, in a case when a sheet with relatively small (weak) stiffness is discharged to the sheet discharge tray, a front end of the sheet might hangs down under its own weight and the sheet is not stacked orderly on the sheet discharge tray.
Then, Japanese Patent Application Laid-open No. 2009-190809 discloses an image forming apparatus including a sheet discharging apparatus having a stiffness imparting unit, which imparts stiffness to a sheet by pressing and bending the sheet in a width direction intersecting with a sheet discharging direction.
By the way, there is a case when a sheet processing device, which conducts such process as stapling on a sheet on which an image has been formed, is mounted on the sheet discharge tray of the image forming apparatus. Here, in a case in which a sheet with a curve in the width direction is conveyed to the sheet processing device, the sheet might cause jamming within the sheet processing device or damage of the image for coming into contact with a member near a conveyance path. Then, it is preferable to take the stiffness imparting unit out of the sheet discharging apparatus in advance of mounting the sheet processing device on the sheet discharge tray. However, such jamming of the sheet and damage of the image as described above might occur in a case where an user erroneously mounts the sheet processing device on the sheet discharge tray while the stiffness imparting unit remains assembled in the sheet discharging apparatus.